The Old Mill is a Silly Symphonies cartoon produced by Walt Disney Productions, directed by Wilfred Jackson, scored by Leigh Harline, and released theatrically to theatres by RKO Radio Pictures on November 5, 1937. The film depicts the natural community of animals populating an old abandoned windmill in the country, and how they deal with a severe summer thunderstorm that nearly destroys their habitat. It incorporates the song "One Day When We Were Young" from Johann Strauss II's operetta The Gypsy Baron.

The Old Mill was the first Silly Symphony cartoon to be released by RKO and was added a new Silly Symphony logo, some new titles, and a burlap background which was used for several other Disney theatrical cartoon series like Donald Duck, Goofy, Mickey Mouse, and Pluto the Pup.

Like many of the later Silly Symphony shorts, The Old Mill was a testing ground for advanced animation techniques. Marking the first use of Disney's multiplane camera, the film also incorporates realistic depictions of animal behavior, complex lighting and color effects, depictions of wind, rain, lightning, ripples, splashes and reflections, three-dimensional rotation of detailed objects, and the use of timing to produce specific dramatic and emotional effects. All of the lessons learned from making The Old Mill would subsequently be incorporated into Disney's feature-length animated films, such as Snow White and the Seven Dwarfs (1937), which was released a month later, as well as Pinocchio (1940), Fantasia (1940) and Bambi (1942).

In 2015, the United States Library of Congress selected the film for preservation in the National Film Registry, finding it "culturally, historically, or aesthetically significant".